A New Polyketide-Derived Metabolite with PTP1B Inhibitory Activity from the Endophytic Fungus Pestalotiopsis neglecta

A new polyketide-derived metabolite, named neglectine A, was isolated from cultures of the endophytic fungus Pestalotiopsis neglecta. Its structure was elucidated by analysis of 1D and 2D spectroscopic data as well as MS. Neglectine A possessed a rare bis-tetrahydrofuran ring system and showed moderate activities against SHP1, CDC25B, and PTP1B, with IC50 value of 17.1 μg/mL, 24.0 μg/mL, and 6.7 μg/mL, respectively. It is important to note that neglectine A has exhibited significant selectivity between PTP1B and CDC25B, LAR, SHP1, and SHP2. This is the first time that neglectine A is reported to have significant PTP1B inhibitory action.